Flow channel structure is incorporated in chemical assay chips for analyzing glucide, lipid, blood, and protein, such as antigens and DNA.
FIG. 17 is a perspective view of conventional chemical assay chip 1 described in JP2007-292527A. The chemical assay chip is used for analyzing an antigen-antibody reaction for instance, and includes inlet port 2 for introducing an analyte solution including antigen, and flow channel 3 for transporting the introduced analyte solution to reaction region 4. The antigen in the transported analyte solution is reacted with antibody inside reaction region 4. After the reaction, the analyte solution is colored due to enzyme reaction or the like, and a concentration of the antigen is analyzed by measuring a degree of the coloration with a thermal lens microscope or the like.
In this type of chemical assay, it is necessary to thoroughly mix the solution, such as the analyte solution, in flow channel 3 and to obtain uniform distribution of the concentration. It becomes possible to accelerate the reaction in reaction region 4 or to improve the detecting accuracy in the detection region by homogenizing the solution in flow channel 3. However, the analyte solution may not become homogenized while the solution passes through flow channel 3 of chemical assay chip 1. If the analyte solution is not homogeneous, the reaction becomes slower or the detecting accuracy decreases, thereby resulting in degradation in performance of the chemical assay chip.